Indigo Renderer Forum

Hello,

I am having troubles with exit portals in Sketchup.
I drew a room with some windows. Drew some rectangles on the outside and assigned a material to it which i configured as exit portal in Skindigo
There are no lights inside the room. When i render, i get all black image
If i remove one portal just for test, i get some light. So i thought to reverse the faces. The weird thing is that this rectangle is 2-sided. So i assigne the exit portal to that other face (do not know if i am supposed to) and rendered again, but it is still black

Am i doing something stupidly wrong here? I searched this forum on exit portals in sketchup.. but i came up emtpy.. or i did not search correct

What am i doing wrong with the exit portals? or do i need to draw rectangles that are not 2-sided and how do i do that then?

Your normals have to face inwards. iirc. its all a normals thing. i think theres a tutorial somehwere on exit portals, but yeah i think its supposed to face towards the camera to let the light in but not back out.

or at least thats how it works in blender.

Yes.. i can use exit portals the way you described in blender. But i wanted to try out the new skindigo and came across this.

I tried to flip the surface. but i think it is my lack of knowledge of sketchup. Because when i flippend the exit portal surface.. i ended up with the other side (which had no mat assigned) so i do not think i am doing it right

I searched and came up with the 'monochrome' view to check the facings (normals i guess). i still cannot get it right

The front side of the face should point inwards. Switch to monochrome mode by going to view > face style > monochrome. If the face is blue, it's facing the wrong direction. Right click it, and from the context menu, choose "Reverse Faces".

Ok, all clear.

But when i flip faces.. i seam to get another face which does not have any materials assigned to it.. In fact i can assign a brick wall mat to 1 side, flip it and make it a nice yellow paint on the other side. Doesnt that mean that my rectangle has thickness? and that is not good when using exit portals i think.

they are just two sided. not thick in that definition. many renders have some issues with the front and back planes of sketchup faces.
try to get the white side to "front" and you dont have any problems in any programms.
sometimes its a little bit hard to see which is front and which is back, even in monochrome mode. you can change the colors in styles->edit->face settings. just change to something that can differ easily. my standart style has front to a light blue and backface to a warning red. that does not change any colors of you model, just the colors sketchup uses for monochrome mode

aslocum wrote:they are just two sided. not thick in that definition. many renders have some issues with the front and back planes of sketchup faces.
try to get the white side to "front" and you dont have any problems in any programms.
sometimes its a little bit hard to see which is front and which is back, even in monochrome mode. you can change the colors in styles->edit->face settings. just change to something that can differ easily. my standart style has front to a light blue and backface to a warning red. that does not change any colors of you model, just the colors sketchup uses for monochrome mode

That is one nice tip. Thank you. Hope to post some render up soon (if it is worthy though)